The U.S. Northern Command and Coast Guard have launched a major field-training exercise off Alaska’s northwest coast. Arctic Chinook is intended to demonstrate how local, state and federal agencies would respond to a simulated cruise ship accident. Coincidentally, a big luxury cruise ship will sail through the area while the exercise is under way. And to further complicate things, bad weather has just set in.

Scientists say warm winter weather around the circumpolar north has led to another record-setting year of decreasing sea-ice coverage of the Arctic Ocean. The extent of sea ice formed over this past winter fell short of the previous record-low extent set last year.